Abaixo está uma instrução que descreve uma tarefa de geração de SQL, combinada com uma entrada que fornece mais contexto sobre os esquemas de tabela disponíveis. Escreva o código SQL que responda adequadamente à solicitação
 ###Instrução: Qual é a média dos que têm entre $70-80 mil e possuem 2.80%?
 ###Tabelas: CREATE TABLE past_champions_and_grand_finalists (past_champions_and_grand_finalists_id AUTO_INCREMENT PRIMARY KEY, Year INT, Champion VARCHAR, Grand Finalist VARCHAR, Champion Team Members VARCHAR, Grand Finalists VARCHAR) CREATE TABLE seasonal_timeslots_ratings (seasonal_timeslots_ratings_id AUTO_INCREMENT PRIMARY KEY, Season INT, TV season VARCHAR, Regular Timeslot (EDT) VARCHAR, Episode count INT, Season premiere VARCHAR, Season finale VARCHAR, Rank VARCHAR, Rating VARCHAR) CREATE TABLE faculty_and_staff (faculty_and_staff_id AUTO_INCREMENT PRIMARY KEY, Data VARCHAR, Headcount INT, Percent of total VARCHAR, Less than $25,000 VARCHAR, $25,000 to $40,000 VARCHAR, $40,000 to $50,000 VARCHAR, $50,000 to $60,000 VARCHAR, $60,000 to $70,000 VARCHAR, $70,000 to $80,000 VARCHAR, More than $80,000 VARCHAR, Mean VARCHAR) CREATE TABLE current_member_schools (current_member_schools_id AUTO_INCREMENT PRIMARY KEY, School VARCHAR, Location VARCHAR, Enrolment INT, Founded INT, Denomination VARCHAR, Boys/Girls VARCHAR, Day/Boarding VARCHAR, Year Entered Competition INT) CREATE TABLE round_of_16 (round_of_16_id AUTO_INCREMENT PRIMARY KEY, Home team VARCHAR, Home team score VARCHAR, Away team VARCHAR, Away team score VARCHAR, Ground VARCHAR, Crowd INT, Date VARCHAR, Time VARCHAR)  
SELECT Mean FROM faculty_and_staff WHERE $70,000 to $80,000 = 2.80%